A conventional fluid machine includes a rotation unit that is rotatably disposed, has a hub and a plurality of blades, and transmits energy between the rotation unit and a fluid. For example, in a blower, axial pump, propeller, cooling fan, ventilation fan, or the like, the rotation unit is rotated so as to convert mechanical energy to fluid energy, whereas in a wind turbine, steam turbine, hydro-turbine, or the like, fluid energy is converted to mechanical energy so as to rotate the rotation unit.
However, in the above-mentioned conventional fluid machine, the blades are formed to project radially outwardly from the hub, and hence the blades are easily damaged upon reception of external force and have poor durability.
In addition, as the rotation unit rotates, vortexes are generated at the tips of the blades, and such tip vortexes cause vibration of the blades and generation of noise.
An object of the present invention is to solve the above-mentioned problems involved in the conventional fluid machines and to provide a fluid machine which can improve the durability of wings and suppress vibration of the wings and generation of noise.